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Objective To discuss the value of detection of small liver tumor with Galactose-Bovine-serum-albumin containing superparamagetic(Gal-BSA-SPIO) in rabbits primarily.Methods Gal-BSA-SPIO was obtained by stabilizing small superparamagnetic iron with galactose-bovine-serum-albumin,and its size was measured.Models of liver tumor(diameter＜1.5 cm) in rabbits were founded.The animals were randomly divided into groups of SPIO (n=10) and group of Gal-BSA-SPIO (n=10).Each group was further subdivided as 5 μmol Fe/kg group (n=5) and 10 μmol Fe/kg group (n=5),respectively.All animals were performed magnetic resonance imaging before and after administration of agents according to groups.SE T2WI,FSE T2WI and GRE T2WI sequences were used.Then signal of noise(SNR) of liver and contrast-noise ratio(CNR) of tumor-liver were measured and compared statistically.The histopathology study was performed for liver and tumor specimens after MR imaging.Results The mean value for the volume size was 34.4 nm,and the core particle size was 14.8 nm.The differences of liver SNR between before and after enhancement for 5 μmol Fe/kg SPIO,5 μmol Fe/kg Gal-BSA-SPIO,10 μmol Fe/kg SPIO and 10 μmol Fe/kg Gal-BSA-SPIO group were (1.92±0.42),(3.75±0.51),(3.25±0.72) and (4.73±0.34) on SE sequence,respectively;(1.56±0.18),(3.56±0.64),(3.33±0.16) and (4.83±0.16) on FSE sequence,respectively;(5.55±0.91),(9.58±0.66),(9.20±0.29) and (10.63±0.32) on GRE sequence,respectively.There were significant differences between all groups for difierent doses and agents and within all different sequences (P＜0.01).The differences of tumor-liver CNR between before and after enhancement of these 4 groups were(2.22±0.68),(5.27±0.22),(4.25±0.51) and (6.97±0.63) on SE sequence,respectively;(1.73±0.41),(4.46±0.54),(3.73±0.49)and (5.39±0.39) on FSE sequence,respectively;(5.98±0.71),(11.79±0.57),(9.57±0.54)and(14.64±1.35)on GRE sequence,respectively.The differences between all groups of different doses and agents and within all sequences showed significant (P＜0.01). Histopathological study revealed that Gal-BSA-SPIO was mainly distributed in hepatocytes while SPIO mainly in Kupffer cells.Conclusion Gal-BSA-SPIO is a agent with good negative enhancement effect in liver.It may be helpful for detecting small tumor of liver.
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Objective To investigate the clinicopathologic features and imaging findings of several kinds of rare and uncommon brain embryonal tumours. Methods MRI or CT appearance and clinicopathologic features in 10 eases of histopathology confirmed brain embryonal tumours were retrospectively analyzed.Results Among 10 cases,there were supratentorial primitive neuroectodermal tumour(sPNET) in 6,ependymoblastoma in 2,medulloepithelioma and atypical teratoid/rhabdoid tumour (AT/RT)in 1 respectively.Patients in 4 cases were infancy and childhood.There was characteristic of the clinicopathologic features of tumors that were the evidence of accurate diagnosis. All lesions were located in the supratentorial region.The tumors were large,usually lobulated in shape irregularly and showed heterogeneous density or signal intensity with some cystic and necrotic areas.The tumors parenchyma appeared slightly high density on CT imaging,iso-or high signal on T2WI and slight low signal on T1WI with intense enhancement after contrast injection.Conclusion MRI or CT findings of rare and uncommon brain embryonal tumours were not characteristic,it Was very essential to know the tumors combined with the clinical and pathologic features.